等级IXLC在已实现列车定位和有效的ITC移动授权条件下可转换到（）。
A.CTC
B.ITC
C.IXL
D.RM
参考答案：B
----Mr. Johnson, would you have some more ice-cream?
----No, thanks. It’s very good, but I have to _____ my weight, you know.
A．remain
B．notice
C．watch
D．care
数组Dim x(3，-1 to 1,6)包含元素的个数有【7】。
